Gas turbine combustor having helically directed openings to admit steam and secondary air



April 28, 1953 R. E. ZOLLER 2,635,345

GAS TURBINE COMBUSTOR HAVING HELICALLY. DIRECTED OPENINGS T0 ADMIT STEAM AND SECONDARY AIR Filed March 19, 1948 2 SHEETS-SHEE' 1 1 34. //I\\ 8TAM F- J INVENTQR g am/d ZZd/er Patented Apr. 28, 1953 GAS TURBINE COMBUSTOR- HAVING HELI- CALLY DIRECTED OPENINGS TO ADMIT STEAM AND SECONDARY AIR Ronald Ernest Zoller, London, England, assignor to The Babcock & Wilcox Company, Rockleigh, N. J., a corporation of New Jersey Application March 19, 1948, Serial No. 15,832

In Great Britain March 21, 1947 7 Claims( (01. 6039.55)

This invention relates to furnaces and particularly to furnaces adapted to operate under pressure and suitable for supplying hot gases to gas turbines. In order to obtain complete and rapid combustion in a small space, combustion Within a gas turbine furnace must take place at high temperature. There is therefore not only a considerable internal pressure, but also a high temperature within the furnace, with a result that gas. turbine furnaces have suffered from low availability. Particularly diflicult conditions arise when a furnace is arranged to effect interstage reheating since the gases entering the furnace are already at a substantial temperature. An object of the invention is the provision of furnaces of improved reliability.

Since the products of combustion are at too high a temperature for use in a gas turbine they must be cooled and the cooling is generally accomplished by the addition of relatively cool gaseous fluid. The mixture of the products of combustion and cooling. gaseous fluid should reach the turbine in unstratified condition and other object of the invention is the provision of means for promoting rapid and thorough mixing of the products of combustion and cooling gaseous fluid.

' The present invention comprises a furnace for the generation of gases under pressure for a gas turbine having a combustion space which is surrounded by a wall faced internally with refractory material in which are embedded metal elements projecting inwardly towards the combustion space from tubes adapted for the flow of coolingfluid therethrough and which is enclosed within a metal casing adapted to resist pressure and at a distance from the wall to leave a space between the casing and the wall at least part of which space is occupied by a passage surrounding the combustion space and adapted for the flow of cooling gaseous fluid therein.

The metal elements may include studs arranged for keying or holding the refractory material, most suitably chrome ore. Fins or other extended surface elements may be used as the metal elements.

The invention moreover includes alfurnace comprising a casing adapted to withstand internal pressure and a tubulous jacket surrounding a combustion space within the casing and adapted to conduct cooling fluid and discharge thefluid into the furnace gases. i

The invention furthermore includes a furnace comprising a casing adapted to withstand internal pressure, an inner hollow jacket surrounding a combustion space within the casing and adapted to conduct cooling fluid, an outer hollow jacket spaced from the inner jacket and from the casing and adapted to conduct coolingfluid, common means for supplying gaseous fluid to the combustion space and to the space between the jackets and separate means for supplying gaseous fluid to the spacebetween the outer jacket and the casing.

The invention furthermore includes a furnace comprising a casing adapted to withstand internal pressure, a hollow jacket surrounding a combustion space within the casing and adapted to conduct cooling fluid, means for adding cooling gaseous fluid to the products of combustion and means for providing a mixing jet or mixing jets of elastic fluid adapted to promote mixing of the cooling gaseous fluid and products of combustion.

Two forms of furnace chamber accordin to the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 represents partly diagrammatically a longitudinal cross-section of a furnace for the generation of gases for a high-pressure gas turbine;

.pressure turbine;

- Figure 3 is to a larger scale than Figures 1 and 2 and shows the arrangement of studs on the surfaces facing towards the combustion space of tubes of the wall surroundin the combustion space, as seen before the application of refractory thereover; and

Figure 4 shows a cross-section on the line IVIV of Figure 3, and shows also refractory in place over the tube surfaces.

Referring to Figure 1, the furnace chamber 2 comprises a pressure resisting casing 30 of genof the pressure casing. The cooled-wall structure a steam cooled wall structure 3i having a cylindrical wall 32 spaced from the cylindrical wall of the pressure casing. The cooled wall structure is formed'at one end with a firing opening 33 centrally within which is arranged a steam atomising oil burner I3 having an impeller plate 34 around the nozzle thereof and designed to cause air entering the combustion space immediately around the nozzle to have a whirling motion around the nozzle, and provided with the usual adjustable louvres 35 between which flows the air arranged to enter through the firing opening into the combustion space 56 within the cooled wall structure, and at its other end the cooled wall structure is formed with an opening 37 for the exit of gases from the combustion space. The cylindrical wall 32 of the cooled wall structure and the end wall 38 at the end of the combustion space around the exit opening are formed by chrome ore refractory material 200 (Figure 4) applied while in a plastic condition over the surfaces facing inwardly towards the combustion space of twenty-four tube coils 39, such surfaces being provided with metal studs iiili (Figures 3 and 4; the scale of Figure 1 does not allow the studs to be represented therein). Part of one of the tube coils 39 is arranged to define the end wall 48 of the combustion space around the firing opening. A further tube coil ll is arranged to form a passage 32 with converging walls through which the gases from the combustion space must flow before reaching the exit opening. The pressure casing is formed with an internally extending portion 43 forming a diverging passage is for the gases leaving the combustion space 3E, and the walls of such passage are also lined with the tube coil 4!. At the outer end of the diverging passage 46 the pressure casing is formed with a flange 2H) for mounting the furnace on a gas turbine casing.

The various tube coils are cooled by the passage therethrough of steam led thereto by an inlet 45 extending through the pressure casing into a header 46 which is arranged longitudinally in the pressure casing and into which the steam inlet ends of the tube coils connect. Each tube coil is led in the cylindrical and end walls of the cooled wall structure a suitable number of times around the axis of the combustion space and terminates in a steam outlet nozzle 47 arranged to deliver steam passing through the coil into the combustion space with a whirling motion therearound in the same direction as the whirling motion of air produced by the impeller plate 34 and as a stream flowing initially at least in part in contact with the adjacent wall. The nozzles 41 in which the tube coils 39 of the cylindrical and end walls terminate are arranged in four rows spaced longitudinally of the combustion space with six nozzles in each row spaced evenly around the cylindrical wall 32. The tube coil 4| around the converging passage to the exit opening and the diverging passage therefrom terminates in a nozzle 41 arranged to deliver into the gases shortly after they have entered the converging passage and in a stream initially at least partly in contact with the walls of the passage and having a whirling motion around the passage in the same direction as the whirling motion of air produced by the impeller plate 34.

The pressure casing is formed at the gas exit end thereof with an inlet 48 for the entry of compressed air supplied by a high pressure compressor.

of gases flowing from the exit opening, through eight apertures 49 formed in the wall of the diverging passage and arranged in pairs, evenly spaced around the passage. The other part of One part of the air entering the pres- 1 .sure casing is arranged to flow into the stream the air is arranged to flow into the annular space 50 between the pressure casing and the vapour cooled cylindrical wall, whence some of the air enters the combustion space through ports 51 formed in the said cylindrical wall and inclined so as to give to the entering air a whirling motion around the combustion space in the same direction as the whirling motion of air produced by the impeller plate 3d. The ports are arranged in three rows spaced longitudinally of the combustion space and the six ports in each row are spaced evenly around the cylindrical wall. The remainder of the air is arranged to enter the combustion space through the firing opening 33.

The air led to the furnace chamber cools the pressure casing and after entering the combus tion space 35 ensures complete combustion and dilutes and cools the products of combustion issuing from the furnace chamber to the gas turbine. The steam supplied effects a cooling of the wall structure 31 therein by flowing through the tubes thereof and also, after being injected into the combustion chamber by the nozzles, by flowing more or less mixed with air and products of combustion over the inner surface of the cylindrlcal wall 32 with a whirling motion around the combustion space, and effects turbulence which promotes the passage to the turbine of well-mixed unstratified gases. The number and design of the steam nozzles are such that a steam pressure not considerably greater than that in the furnace chamber 2 is sufficient to provide the required how of steam. By arranging that there is only a low pressure difference between the steam inside and the gas outside the cooled wall structure 31, the likelihood is much reduced, or is avoided, that a tube failure would be so serious as to render it necessary to shut down the plant immediately by reason of exorbitant steam loss or starving of other tubes.

Referring to Figure 2, the furnace chamber 4 comprises a pressure resisting casing 89 of generally cylindrical form having arranged therein two cooled wall structures 8i and 82 spaced from one another and from the cylindrical walls of the pressure casing. The inner cooled wall structure 82 is formed at one end with a firing opening 83 centrally within which is arranged a steam atomising oil burner 14 having an impeller plate 84 arranged around the nozzle thereof and designed to cause the air flowing immediately adjacent the nozzle towards the combustion space to have a whirling motion around the nozzle, and provided with the usual adjustable louvres 85 between which flows the air arranged to enter through the firing opening into the combustion space 88 within the inner cooled wall structure 82, and at the other end the cooled wall structure is formed with an opening 87 for the exit of gases from the combustion space. The cylindrical walls 88 of the inner cooled wall structure and the end wall 89 at the end of the combustion space around the exit opening are formed by chrome ore refractory material applied while in a plastic condition over the surfaces facing inwardly towards the combustion space of twenty-four tube coils 98, such surfaces being provided with studs in the same manner as the tubing 39 of Figures 3 and 4. Part of one of the tube coils 98 is arranged to define the end wall 9! of the combustion space around the firing opening. A further tube coil 92 arranged to form a passage 93 with converging walls through which the gases from the combustion space must flow before reaching the exit opening. The pressure casing is formed with an internally extending portion 94 forming a diverging passage 95 for the gases leavin the combustion space, and the walls of such passages are also lined with the tube coil 92. At the outer end of the diverging passage 95 the pressure casing is formed with a flange 220 for mounting the furnace on a gas turbine casing.

The various tube coils are cooled by the passage therethrough of steam led thereto by an inlet 96 extending through the pressure casing into a header 9'! which is arranged longitudinally in the pressure casing in the space 98 between the inner and outer cooled wall structures. Each tube coil is led a suitable number of times around the axis of the furnace chamber and terminates in a steam outlet nozzle 99 arranged to deliver steam which has passed through the coil into the combustion space with a whirling motion therearound in the same direction as the whirling motion of air produced by the impeller plate 84, and as a stream flowing initially at least in part in contact with the adjacent wall. The nozzles 99 in which the tube coils 90 of the cylindrical and end walls of the inner cooled wallstructure terminate are arranged in four rows spaced longitudinally of the cylindrical wall with six nozzles in each row spaced evenly around the wall. The tube coil 92 around the converging passage 93 to the exit opening 81 and the diverging passage 95 therefrom terminates in a nozzle 99' arranged to deliver into the gases shortly after they have entered the converging passage and in a stream initially at least partly in contact with the wall of the passage and having a whirling motion around the passage in the same direction as the whirling motion of air produced by the impeller plate 84.

The outer cooled wall structure 8| extends longitudinally in the casing at one end as far as the end wall 89 in which the exit opening 81 is formed, and at the other end to about as far as the louvres 85 of the burner. In the cylindrical wall of the pressure casing an inlet I I0 is formed for the admission of compressed air supplied by a low pressure compressor to the annular space I l I between the outer cooled wall structure 81 and the pressure casing at the end of the space remote from the burner. From the air inlet III] the air is arranged to flow in the annular space III towards the burner and a part of the air enters the combustion space through the firing opening 83. The remainder of the air enters the annular space 98 between the cooled wall structures.

The outer cooled wall structure 8I includes twenty-four tube coils [I2 cooled by the steam from the steam header 91, and these tube coils are so connected in the steam flow that the steam flows in twenty-four parallel flow paths from the steam header first into the tube coils H2 of the outer cooled wall structure 8| and theme by respective connecting tubes (not shown) extending across the annular space between the inner and outer cooled wall structures to respective tube coils of the cylindrical and end walls of the inner cooled wall structure 82.

The pressure casing is formed at the gas exit end thereof with an inlet II3 for the entry of gases from a high pressure gas turbine. One part of these gases is arranged to flow into the stream of gases flowing from the exit opening, through eight apertures H4 formed in the Wall of the diverging passage 95 and arranged in pairs evenly spaced around the passage. The remainder of the gases is arranged to flow into the annular space 98 between the cooled wall struc ture.

From the annular space 98 gaseous fluid enters the combustion space with a whirling motion therearound in the same direction as the whirling motion of air produced by the impeller plate 84, by flowing through inclined ports I I5 formed in the cylindrical wall 88 of the inner cooled wall structure. The ports are arranged in three rows spaced longitudinally of the combustion space and the six ports in each row are spaced evenly around the Wall.

The furnaces described are adapted for long availability and for adequate cooling with high combustion temperatures for ensuring rapid combustion of oil.

I claim:

1. In a furnace for the generation of gases under pressure for a gas turbine, a metallic pressure resisting casing, fluid conducting tubes arranged in the formation of a wall within the casing and spaced therefrom to provide a passage for the flow of cooling gaseous fluid, metallic studs integral with the metal of the tubes and projecting from the sides of the tubes opposite said casing,.high temperature refractory material covering thestuds and the inner faces of the tubes to form the face of the wall of the combustion chamber, the wall of the combustion chamber being formed with a plurality of inclined ports for the admission into the combustion space of cooling gaseous fluid with a whirling motion from the passage outside the wall, means for firing the combustion chamber, means for discharging cooling fluid from said tubes into the furnace gasesin the combustion space before the gases leave the furnace, said last name-d means being arranged to discharge fluid with a whirling motion around the combustion space, means for providing said tubes with a cooling fluid, and means providing a furnace gas outlet from the combustion space, said last named means including a wall projecting into the combustion space and defining a converging passage for gases to the outlet anda further wall which defines a diverging outlet passage for the gases from the combustion space.

2. In a furnace for the generation of gases under pressure for a gas turbine, a metallic pressure resisting casing, fluid conducting tubes arranged in the formation of a wall within the casing and spaced therefrom to provide a passage for the flow of cooling gaseous fluid, me-

tallic studs integral with the metal of the tubes and projecting from the sides of the tubes opposite said casing, high temperature refractory material covering the studs and the inner faces of the tubes to form the face of the wall of the combustion chamber, the wall of the combustion chamber being formed with a plurality of inclined ports for the admission into the combustion space of cooling gaseous fluid with a whirling motion from the passage outside the wall, means for firing the combustion chamber, means for discharging cooling fluid from said tubes into the furnace gases in the combustion space before the gases leave the furnace, said last named means discharging fluid from said tubes of the wall into the combustion space with a whirling motion in the same direction around the combustion space as the cooling gaseous fluid entering the combustion space through the inclined ports, means-for providing said tubes with a cooling-fluid, and meansproviding a furnace'gas 7 outlet: from the: combustion space, said last named means including a wall projecting into the combustion space and defining a converging passage for gasesto the outlet-and a further wall which definesa divergingoutletpassage for the gases from the combustion, space.

3. In a gasturbine combustor for the generation of gasesv under pressure, combustion chamber wall means including contiguous wall tubes normally providing for the flow of cooling fluid therethrough, the wall means also includingmetallicextended surface elements secured in good heat transfer relationship to the tubes and projectingfrom the combustion chamber sides of the tubes, high temperature refractory material covering-the sides of the tubes toward the combustion chamber face of the wall means, burner means firing the combustion chamber, a metallic pressure resistant casing enclosing the combustion chamber and spaced outwardly therefrom to provide a combustion chamber encompassing space, second wall means including similar wall tubes-for the how of cooling fluid therethrough, said second wall means being disposed at a position intermediate the first wall means and the casingand dividing said space into twocombustion chamber enveloping spaces, and normally directing the how of a gaseous cooling medium to said spaces and from said spaces to the combustion chamber at distributed positions and to the firing means.

4 In a gasturbine combustor for the generation of gases under pressure, combustion chamber wall means including contiguous wall tubes normally providing for the flow of cooling fluid therethrough, the wall means also including metallic extended surface elements secured, in good heat transfer relationship to the tubes and projecting from the combustion chamber sides of the tubes, high temperature refractory material covering the sides of the tubes toward the combusticn chamber face of the wall means, burner means firing the combustion chamber, a metallic pressure resistant casing enclosing the combustion chamber and spaced outwardly'thereirom to provide a combustion chamber encompassing space, second wall means including similar wall tubes for the flow of cooling fluid therethrough, said second Wall means being disposed at a position intermediate the first wall means and the casing and dividing said space into two combustion chamber enveloping spaces, said firing means including a device imparting a whirling motion to the gases within the combustion chamber, angularly directed nozzles fed with fiuidby said tubes and directedso asto augment the whirling motion of the gases within the coin bustion chamber by their angular jets, and means normally directing the how of a gaseous cooling medium to said spaces and from said spaces to the firing means and to the combustionchamber at distributed positions.

5. In a gas turbine combustor for the generation of gases under pressure, cylindrical combustion chamber wall meansincluding contiguous wall tubes normally having steam flow therethrough, the wall means also including metallic extended surface elementssecured in good heat transfer relationship to the tubes and projecting from the combustion chamber-sides of the tubes, high temperature refractory material covering the sides of the tubes toward the combustion chamber and surrounding the studs. to form the combustion chamber; face of the wall means, burnermeans firing the combustion chamberwith a whirling motion ofv the combustion elements, a metallic pressure resistant cylindrical casing en closing the combustion chamber and spaced outwardly therefrom to provide a combustion chamber encompassing space, means normally directing the flow of a gaseous cooling medium to said space and from said space to the firing means and to the combustion chamber at distributed positions, inclined nozzles fed by the steam heating tubes and so directed through the combustion chamber wall at distributed positions as to augment the whirling action initiated by the firing means, and a gas mixing combustion chamber outlet of venturi-like construction involving similar steam heating wall tubesand a similarly: inclined steam nozzle.

6. In a gas turbine combustor for the generation of gases under pressure, hollow cylindrical combustion chamber wall means including contiguous wall tubes normally'having steam flowing therethrough, the wall means also including metallic extended surface elementssecuredin good heat transfer relationship to the tubes and pro,- jecting from the combustion chamber sides of the tubes, high temperature refractory material covering the sides of the tubes toward the combustion chamber face of the wall means, burner means firing the combustion chamber with a whirling motion of the combustion elements, a metallic pressure resistant cylindrical casing enclosing the combustion chamber and spaced outwardly. therefrom to provide an intervening combustion chamber encompassin space, second hollow cylindrical wall means including similarwall tubes normally having steam flowing therethrough, said second wall means being disposed at a position intermediate the first wall means and the casing and dividing said space into two combustion chamber enveloping spaces, first firing means including a device imparting a whirling motion to the gases within the combustion chamber, angularly directed steam nozzles fed by said tubes and directed through the combustion chamber wall so as to augment the whirling motion of thegases within the combustion chamber by their angular jets, and means normallydirecting the flow of a gaseous cooling medium to said spaces and from said spaces to the firing means and to the combustion chamber at distributed positions.

'7. In a gas turbine combustor forthe generation of gases under pressure, wall means defining a combustion chamber of hollow cylindrical shape, burner means firing the combustion chamber at one end thereof with a whirling motion of the combustion elements, a metallic pressure resistant cylindrical casing enclosing the combustion chamber and spaced outwardly therefrom to provide a. substantially annular space for, av gaseous combustion supportin medium, means normally directing a'flow ofgaseous combustion supporting mediumto said space and to the firing means, means forming a combustion chamber outlet at the end of the combustion chamber opposite the firing means, substantiallycircumferentially and helically directed nozzle means distributed over the length of the combustion chamber and extending through its wall and arranged tolclirect jets ofa gaseous cooling, medium substantially helically of the combustion chamber and toward the combustion chamber, gas outlet, means for supplying said, nozzle means with the; gaseous cooling mediumunder pressure, the temperature of said medium suppliedto the nozzle means being substanti lly: le s. han he-t mperature or the 9 combustion elements igniting in front of the firing means, said combustion chamber wall means being formed with openings distributed over the area of the wall means and directing the gaseous combustion supporting medium from said annular space somewhat helically and toward the combustion chamber outlet.

RONALD ERNEST ZOLLER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 660,996 Nicholson Oct. 30, 1900 1,237,877 Dow Aug. 21, 1917 1,781,236 Lilge Nov. 11, 1930 1,840,690 Bissell Jan. 12, 1932 Number Number Name Date Goddard Oct. 8, 1935 Bailey et a1 Sept. 5, 1944 Lubbock Apr. 16, 1946 McCollum July 2, 1946 Bonvillian et a1 Mar. 22, 1949 Goddard Sept. 20, 1949 Bonvillian et a1 Oct. 2, 1951 FOREIGN PATENTS Country Date Great Britain Dec. 1, 1904 Great Britain Feb. 24, 1908 Great Britain Apr. 7, 1908 Great Britain Apr. 6, 1937 Great Britain Dec. 6, 1944 

